This invention relates to the field of systems used in electrical installations to connect electrical cables, and particularly power cables, to each other. In particular, it relates to the field of power breaker strip with terminals.
The invention thus specifically discloses a power breaker strip for fixed-pitch connection of several electrical cable lines, and an electrical installation containing it and a method of assembling such a power breaker strip.
It is applicable mainly in the field of aeronautics, particularly for electrical equipment installed onboard an aircraft.
The use of power breaker strip with terminals (hereinafter called “breaker strip” for simplification) to connect electrical power cables in an electrical installation, and particularly an electrical installation onboard an aircraft may be necessary for various reasons and more particularly for industrial and/or technical reasons.
Industrially, the use of a breaker strip is used mainly to connect assemblies on which electrical systems are pre-installed. Furthermore, for the special case of a breaker strip of the type described below with reference to FIG. 1, the breaker strip may also be used to connect power distribution cables output from an electrical core to the corresponding power cables located on the general circuit of an aircraft.
Technically, the use of a breaker strip can modify the nature and/or the size of power cables. The rules and conditions applicable outside and inside electrical boxes are different, such that cables optimised for their context have to be used. For example, since electrical cores have internal conditions with higher temperatures, lower bending radii and shorter circuit lengths, the choice of copper electrical cables is preferred. On the other hand, in the lack of such external conditions, aluminium (lighter weight) electrical cables can be used.
Several examples of breaker strips for the connection of power cables are already known in the prior art. FIGS. 1 to 3 show an example embodiment of such a breaker strip.
FIG. 1 shows a perspective view of a breaker strip 1 used for the connection of power cables 2. The breaker strip 1 comprises a metal support 3 on which a set of terminals 14 is fixed arranged at a regular pitch along the support 3, each terminal 14 being electrically insulated from adjacent terminals by spacers 4 usually made from polytetrafluoroethylene (PTFE) and by resin cores. FIG. 3 shows details of the connection principle for two power cables 2 at a terminal 14. A metal insert 11 passes through the lugs 10 of the two power cables 2 so that they can be attached by screwing into a resin core 12 located on the metal support 3.
Nevertheless, the use of such a breaker strip 1 is not entirely satisfactory. First, it has a low breaking density, in other words for example, breaking one line among a fairly small number of power cables requires a large amount of space. Each pitch at which there is a terminal 14 between two spacers 4 covers a line of power cables 2, such that the width of the breaker strip 1 increases when the number of power cable lines 2 increases. Furthermore, as can be seen in FIG. 2, the breaker strip 2 according to the prior art has to be adapted on an intermediate structural support 8 before being fixed to the primary structure 9 of the aircraft. In other words, it is not sufficient in itself. Furthermore, such a breaker strip 1 usually has a high total mass due to the use of metal in the support 3 and the inserts 11 integrated into solid resin cores 12. Furthermore, this type of breaker strip 1 cannot change, and the pre-installation of all its elements makes it necessary to keep a maximum mass in flight even if the breaker strip 1 is only partially used. Still furthermore, when considering the environment of an aircraft in which these breaker strips 1 can be used, the width imposed by them (in other words, a line of cables with fixed-pitch breakers) makes it impossible to route and break power cable lines 2 in the same direction.